Create special finishes for printed output in Photoshop
This short article is about a methodology of creating special finish layers as Spot White, Pantone, Matt, Emboss, Deboss, Gloss, Foil for a printed output using Photoshop. In this case will be special finishes saved as separate tiff files and placed to InDesign as pages after CMYK artwork.
Spot White / Pantone Colors
In your CMYK psd artwork document, separate the Spot White layout by creating a new Channel or a new Group and duplicate it into a new window. Make a color overlay (ideally Black with all 4 colors) and flatten the image. Open Image > Mode > Greyscale (Convert the image to Grayscale) and save as TIFF document.
Matt / Emboss / Deboss / Gloss / Foil
In these cases the method is a bit more complicated but starts as previously, separate your required layout necessary for your needs by placing into a new Group or creating a new Channel and duplicate it into a new window. Make a color overlay, flatten the layers and convert it into Grayscale color mode. Open Image (from the top menu) > Image Size > Resolution and change it to 1200 Pixels/Inch. Open Image > Adjustments > Curves and fix the imperfections on a resolution (these will vary depending on your artwork). Next step is converting the file to Bitmap format (Image > Mode > Bitmap) and after that saving it as TIFF.
The final TIFF file should be placed into InDesign next page after CMYK and/or other finishes to create a pdf for print. I am doing it by copying the CMYK artwork, then creating a new page and using paste in place for accuracy. After this re-link the CMYK file with the corresponding TIFF.